Apparatus for making a complexly patterned extrudate

ABSTRACT

Disclosed are apparatus (10) for making a complexly patterned extrudate. The apparatus (10) includes a food cooker extruder (12) for providing at least one extrudable food product, at least one food color supply (18), a pattern forming die (20) for mixing the food color and extrudate food product to form a complexly patterned food product, a reducing passageway for reducing the cross sectional area of the patterned dough from an inlet end (34) to outlet end (36) of at least 50:1 at an average convergence angle of ≦45° and an extruder exit port at the discharge end of the reducing passageway.

FIELD OF THE INVENTION

The present invention comprises apparatus and methods for makingcomplexly patterned multicolored extruded food products. Moreparticularly, the present invention relates to apparatus and methods forreducing a large cross sectional area complexly patterned food extrudateto a smaller area while maintaining the complex pattern.

BACKGROUND

Food products such as Ready-To-Eat ("R-T-E") cereals and snack productsvary widely in composition, shape, color, flavor, texture, etc. Suchproducts can include both puffed and unpuffed varieties. One attractivefeature is their appearance which can include specific attributes suchas shape and coloration. Especially attractive are products having acomplex but organized pattern of coloration, shape and/or complex shape.

A wide variety of techniques are known to provide complexly shapedproducts such as rings, stars, letters, figures, etc. Problems generallyinclude how to provide consistently the desired degree of shape detailor resolution in the finished pieces. Similarly, for colored products, aproblem is how to consistently provide a fine level of detail. Thisproblem of imparting a fine level of detail is particularly difficult inthe provision of complexly patterned R-T-E cereals due to theirgenerally smaller size. The problem is even more severe for puffed R-T-Ecereal products due to the very tiny size of the pellets that areexpanded to form the finished products. Of course, the pellets mustcontain and retain the complex pattern.

In particular, it would be desirable to prepare puffed R-T-E cerealshaving a shape and color pattern reminiscent of various sports ballssuch as baseballs, footballs, basketballs and soccer balls, such as aredisclosed in 1) U.S. Design patent application Ser. No. 014,233, filedOct. 18, 1993 by Laughlin et al. entitled Food Product Piece, 2) U.S.Design patent application Ser. No. 014,068, filed Oct. 12, 1993 byLaughlin entitled Food Product Piece, 3) U.S. Design patent applicationSer. No. 014,474, filed Oct. 22, 1993 by Laughlin entitled Food ProductPiece now U.S. Pat. No. Des. 368,791 issued Apr. 16, 1996, and 4) U.S.Design patent application Ser. No. 014,069, filed Oct. 12, 1993 byLaughlin entitled Food Product Piece now U.S. Pat. No. Des 372,352,respectively, each of which are incorporated herein by reference. Suchproducts are characterized in part by high degrees of resolution such asby line features (such as to indicate traditional sticking patterns) 1mm> in thickness and even 0.5 mm>. Providing a cereal pellet which uponpuffing provides a puffed R-T-E cereal exhibiting such a fineness ofdetail is a difficult problem to overcome.

Line colored or externally striped food products such as R-T-E cerealsas well as apparatus and methods for their preparation are described inU.S. Pat. No. 2,858,217 entitled Cereal Product With Striped Effect andMethod of Making Same (issued Oct. 28, 1958 to J. O. Benson) and whichis incorporated herein by reference. The '217 patent describes anextrudate extruder having a color injecting die insert for making acomplexly patterned extrudate. However, the extrudate is directlyextruded without any reduction in its cross sectional area. Also, themethod appears to be limited to producing only flakes in a simplepattern of generally parallel more or less straight lines. The method isnot capable of generating a direct expanded cereal or snack (i.e.,expanded directly from the extruder) having a line detail of such adegree of fineness.

An improvement or modification in the technique for providing a linecolored cereal based snack piece is described in U.S. Pat. No. 3,447,931(issued Jun. 3, 1969 also to Benson et al.) entitled Process ForPreparing A Puffed, Concave Shaped Cereal Product. More particularly,the '931 patent describes a process for making a cup flower shaped R-T-Ecereal piece having a complex line pattern. The process involvesextruding a plurality of rope dough filaments which are pressed togetherto form a column or rope without a material decrease in the crosssection which is then combined under conditions such that no puffingoccurs. The composite strand of compressed filaments is then cut intowafers and which are subsequently heat puffed. While useful, the processappears to be limited to producing only the "flower bloom" shape. Also,the pieces prepared are of a larger snack piece size rather than therelatively smaller pieces characteristic of R-T-E cereals.

The present invention provides an improvement in apparatus and methodsfor preparing food products characterized by at least two colors in anorganized pattern. In particular, the present invention provides animprovement in the degree of fineness level of color detail (1 mm>) evenon food products such as pellets for puffed R-T-E cereals that are verysmall (e.g., 3 to 6 mm) in diameter.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an end view partially cut away of the die face of a foodcooker extruder showing a plurality of exit ports.

FIG. 2 is a sectional view greatly cut away of a reduction passageway ofthe present invention taken along lines 2--2 of FIG. 1.

FIG. 3 shows an enlarged sectional view of a die insert for making anenlarged complexly shaped dough taken along lines 3--3 of FIG. 2.

FIG. 4 is an enlarged sectional view of a die insert showing thechannels for the food color flow taken along lines 4--4 of FIG. 3.

FIG. 5 is an enlarged sectional view of the die insert taken along lines5--5 of FIG. 4 in an upstream orientation.

FIG. 6 is an enlarged sectional view of the die insert taken along lines5--5 of FIG. 4 similar to FIG. 5 but showing a downstream orientation.

FIG. 7 is an enlarged plan view of a finished puffed complexly patternedR-T-E cereal piece prepared using the present methods and apparatus.

FIG. 8 is an enlarged sectional view of the R-T-E cereal piece takenalong lines 8--8 of FIG. 7 showing the concave shape of the cerealpiece.

Where used in the various figures of the drawing, the same numeralsdesignate the same or similar parts. Furthermore, when the terms "top,""bottom," "first," "second," "upper," "lower," "height," "width,""length," "end," "side," "horizontal," "vertical," and similar terms areused herein, it should be understood that these terms have referenceonly to the structure shown in the drawing and are utilized only tofacilitate describing the invention.

DESCRIPTION

Referring now to the drawing and briefly in particular to FIG. 1, thereis shown an apparatus for preparing a complexly patterned cereal doughpiece according to the preferred teachings of the present invention thatis generally designated 10. In the most preferred form, apparatus 10generally includes a means for providing at least one extrudable foodproduct or cooked cereal dough such as a cooker extruder 12 as seen inFIG. 1. Extruder 12 is seen to have at least one, and more preferably aplurality of exit, ports or orifices 13 each for extruding of acomplexly patterned cooked cereal dough of the present invention (notshown) or other extrudable food product.

While a cooker extruder is the preferred equipment to provide theextrudable food, other conventional equipment and techniques can also beemployed. For example, a batch cooker or semi-continuous cooker forcooking the ingredients in bulk can be equipped with dough forming andconveying extruder element. In other embodiments, e.g., a low moisturefruit paste, a simple screw conveyor can be employed. While in thepresent description particular reference is made to the provision ofcomplexly patterned farinaceous materials such as R-T-E cereals andsnack products, the skilled artisan will appreciate that the apparatusand techniques can be employed with a wide variety of extrudable foodproducts, especially such plastic foods as low moisture fruit products.

Now referring to FIG. 2, the cooker extruder 12 provides the cookedcereal dough in quantity which can supply one or preferably, especiallyin commercial applications, a plurality of passageways 14, each leadingto an exit port 13. In highly preferred embodiments, the apparatus 10can additionally include a means for adjusting the cooked cereal doughflow rate and pressure such as the adjustably retractable dough flowadjuster plug 16 depicted. Such a flow rate adjustment means isparticularly useful when, as in the embodiment depicted, the extrudersupplies a large number of extrudate orifices. Absent such a flow rateadjustment means, the particular extrudate characteristics (e.g.,pressure, mass flow) from each of so many orifices are difficult tocontrol since the length of passageway 14 from the central supply canvary.

The flow adjuster plug 16 can include a rod or bolt 80 having threads 82at its outer end 84 and a smooth portion 86 at its inner end 88. Theplug further includes a means for sealing against dough leaking from theextruder such as at least a first "O" ring 90, 91 inset into a receivingperipheral seal groove 92, 93 respectively. The plug 16 can furtherinclude lock nut 94 which can be tightened against block 96 to securethe plug against movement such as caused by the extruder's vibration.The length of the plug and threading is adjusted so that when fullyextended into passageway 14, the plug 16 will not choke off dough flowso as to minimize dough buildup upstream of the plug 16. In thepreferred form, the length of the plug extending into passageway 14 whenstopped is less than 90° of the width of passageway 14. Dough buildupcan lead to dough hardening and plugging downstream.

Other dough flow adjustment devices can be used with or in substitutionfor the preferred flow adjuster plug 16 herein if 1) positioned upstreamof the die insert 20, and 2) do not increase the likelihood ofdownstream plugging.

The apparatus 10 further essentially includes at least one food colorsupply 18 which can supply a flowable colored food material such as foodcolor liquid (whether oil or preferably water based). The color supply18 is in fluid communication with and the apparatus 10 further includesa means for mixing or forming the food color liquid and extrudable foodproduct into a complexly patterned food extrudate such as a greatlyenlarged (relative to the exit orifice) pattern forming die insert 20depicted. In the preferred embodiment, the passageway 14 can include afirst flared or divergent portion 21 immediately upstream of the dieinsert 20 to widen the passageway 14 to an equal diameter to the dieinsert 20 as well as a second convergent flared portion 22 downstream.In the drawing, the passageway 14 and other constituent elements aredepicted in close to actual size. Thus, the diameter of the die insertdepicted 20 is about 30 mm and is positioned within a slightly enlargedportion 24 of passageway 14. As a result, the diameter of the complexlypatterned dough extrudate as it exits the die insert 20 will have anenlarged initial diameter about 30 mm. Of course, other sizes for thedie insert 20 can be used (e.g., 15 to 100 mm).

In FIG. 2, it can be seen that the complexly patterned dough extrudateso formed then moves through by pressure flow and apparatus 10 furtherincludes a means for reducing the cross sectional area of the complexlypatterned food extrudate while maintaining the pattern such as areducing or necking passageway 25 depicted. The reducing passageway 25can be fabricated from a single piece having, for example, a frustoconical bore or, as depicted, with a plurality of individual pieces suchas the first, second and third pieces 26, 28 and 30, respectively,depicted. Individual pieces can be more easily cleaned. Also, theconvergence angle and other attributes, e.g., internal surface, can beadjusted as needed (e.g., smoothness, anti-stick surface) to accommodatedifferences in the extrudate characteristics of different food products.In FIG. 2, it is seen that the passageway 14 has an initial relativelylarger diameter 34 and a final relatively smaller or exit diameter 36 atthe exit port 13. Moreover, while the passageway 14 is depicted ashaving a circular cross sectional area, in other embodiments thepassageway 14 can be fabricated with a more complex pattern orperipheral configuration to define or define in part the exterior shapeor configuration of the finished piece, including both regular shapes(e.g., stars, rings, ovoids, geometric shapes) as well as irregularshapes (e.g., animals, objects such as trees, cars, etc.). Furthermore,the passageway 14 can be fabricated with an interior surface of desiredcharacteristics, e.g., polished or Teflon or other non-sticking surface,such as to provide decreased friction to facilitate retention of thecomplex pattern or to reduce the pattern's deformation. Especiallydesirable is an ovoid cross section for the passageway for preparationof an American style football or a rugby ball.

An important feature of the present invention is the convergence angleof the reducing passageway 25. It has been found important to maintainan average convergence or confinement angle of 5° to 45° , preferably 5°to 20° , and most preferably 10° to 15° in order to maintain the patternwhile the cross sectional area is reduced. By "average convergence" ismeant the angle formed from the diameter of the die insert 20 to thediameter 36 of exit port 13 over the length of the reducing passageway25. As depicted, with passageway pieces 26, 28, and 30, some pieces,e.g., 26 and 30 have a sharper convergence angle while piece 28 has ashallower angle. Internal obstructions (e.g., shoulders) are to beavoided so as to provide a continuous passageway to minimize disruptingthe complex pattern formed in the dough. FIG. 2 shows that the exitorifice diameter 36 is about 3 mm. Since the passageway 14 can have acomplex cross sectional shape as described above, the extent ofreduction of the pattern is more aptly characterized in terms of crosssectional area reduction rather than more simply a reduction indiameter. Thus the degree of reduction of cross sectional area in theillustrated embodiment is about 100:1. Of course, for other embodiments(e.g., for larger snack pieces), the extent of cross section reductioncan be as little as 25:1. The exit orifice diameter 36 for a snackproduct can be correspondingly larger, e.g., 5 to 15 mm.

Surprisingly, such a shallow convergence angle allows for a reduction incross sectional areas of at least 50:1 and even about 100:1 whilemaintaining a fine level of detail in the complex pattern. Thus, acomplex shape can be imparted to a larger dough face or cross sectionand then reduced to the much smaller desired finish cross sectionalarea. This arrangement allows for the fabrication of a relatively largedie insert to impart the complex pattern. Fabricating a small die insertto impart the desired degree of detail for the final exit diameter whilepossible on a development scale extruder is not commercially practicaldue in part to plugging or fouling of the die insert 20. The provisionof a reducing passageway 25 having the requisite convergence angleallows for the provision of three dimensional shapes to be produced witha fine level of color detail. Moreover, the finished pieces arecharacterized by a color through the entire piece as compared to onlytopical coloration.

Also, it is seen that the mixing is not immediately proximate thedischarge port but distanced therefrom. This allows for the dough tomodestly "set" so as to assist in maintaining the complex shape.

Reference is now made to FIG. 3 which shows an enlarged cross section ofthe pattern forming die insert 20. As can be seen, this particular dieinsert can be used to fabricate a bicolored food piece 40 as seen inFIG. 7 having a swirl or spiral pattern. However, other pattern formingdie inserts can be substituted therefor which, for example, can impartthe line pattern for products reminiscent of soccer balls, basketballs,baseballs and other sports objects.

The die insert 20 includes a means for imparting at least one, and moredesirably a plurality of, dough interstitial gaps such as a plurality ofdough dividing passageways such as passageways 44, 45, and 46respectively formed by die dividing members. The die insert 20 canfurther include a means for injecting a food color or second coloreddough into the interstitial dough gaps such as a plurality or array ofevenly spaced food color injection ports 48 fed by a fluid supplyingpassageway 50 therethrough. The extrudable food product itself may becolored. The color supply 18 may supply a different color or the samecolor having a darker or lighter hue. Specifically, the food colorpassageways 50 are supplied with the food liquid from one or more foodcolor supply ports such as ports 52, 54, and 56, respectively in the diedividing members. Of course, when the second or colored material is afood product such as a second dough or fruit paste, the passageways andinjection ports can be enlarged to reduce friction and the potential forblockage.

Referring now briefly to FIG. 4, it can be seen that the die insert 20can further include a color fluid supply reservoir 58 supplied by thecolor supply 18 and which is in fluid communication with or suppliesfood color supply ports 52, 54, and 56. The die insert 20 can furtherinclude a means for sealing the color fluid supply reservoir 58 againstpremature admixture with dough such as "O" rings 60 and 62 depicted.

Reference is now briefly made to FIG. 5 which shows the upstream face 64of the die insert 22. FIG. 5 shows that the upstream face 64 for thisparticular die insert contains no color supply discharge ports and thatthe discharge of color is preferably in a downstream direction.

Reference is now made briefly to FIG. 6 wherein the relationship betweenthe supply inlet ports, 52, 54, and 56 supply passageways 50 and colordischarge ports 48 can be most simply seen.

Reference now is next briefly made to FIGS. 7 and 8 which show that thefood piece 40 can have a cupped shape and that the coloration can extendthroughout the body of the piece. The piece 40 depicted is a puffedR-T-E cereal piece prepared by direct expansion from the extruder havinga finished diameter of about 70 mm.

In the present invention, the complexly patterned dough of reduced crosssectional diameter is extruded through the reduced diameter exit orifice36 (e.g., about 3 mm). Thereafter, the extrudate is face cut in aconventional manner to form individual pieces such as with one or morerotating knives. Depending upon the conditions of the extrudate, anunpuffed pellet piece can be formed for subsequent puffing, or,alternatively, and preferably herein, a directly expanded finishedpuffed piece is formed. The finished food piece whether subsequentlypuffed or puffed by direct expansion upon exiting the exit orifice 13 isessentially characterized by exhibiting a high resolution or fine degreeof color detail. The detail can include surface line coloration of asthin as about 0.5 mm in the puffed product. In certain embodiments, theinterior is also bicolored or multicolored as well as having topical orsurface coloration.

The extrudable food can comprise a wide variety of conventional foodtypes and in particular can include a fruit paste, potato dough (e.g.,for a fabricated chip) or a cooked cereal dough. The cooked cereal doughcan be for either R-T-E cereals (whether puffed or unpuffed), snackproducts, baked goods, or pastas. Especially desirable are cooked cerealdoughs for puffed R-T-E cereals. Puffed food products such as snacks canbe prepared by hot air puffing, deep fat frying, gun puffing ormicrowave (especially high intensity, e.g., >100 V/cm field strength).Product puffed without deep fat frying can have oil added to thecomposition or have a topical oil application. R-T-E cereals can have asugar coating. Puffed food pieces of the product base (i.e., prior to orwithout oil or sugar) can have a density of about 0.1 to 0.5 g/cc. Thecolored portion forms a line or a plane through the body of the foodpiece. "Highly complex" food products are characterized as having aplurality of colored features at least two of which (e.g., two planes ora line and a plane) intersect within the body of the food piece.

While in the present invention, the particular die insert 20 depicted isdesigned to admix a liquid food color into a cooked cereal dough so asto provide line coloration of extremely fine detail, the die insert 20can be modified (e.g., such as by enlargement of ports 52, 54, and 56fluid passageways 50 and discharge ports 48) to admix two or more cookeddoughs or other flowable colored food materials, especially liquefiedfats (e.g., chocolate, cheese), or fruit paste.

Also, while the particular die insert 20 depicted is designed to providethe swirled finished product depicted, other die inserts can beinterchanged to provide the line coloration detail to provide theparticular desired end products such as the various sports balls (e.g.,soccer, baseball, basketball, American football) referenced above.

It will be appreciated that for those embodiments that are extrudedwithout direct expansion or puffing upon extrusion that lines having adetail of about 0.1 mm in width can be obtained. Upon subsequentexpansion (e.g., deep fat frying, gun puffing, fluidized bed puffing,radiant heat puffing or other puffing methods), puffed pieces will ofcourse expand causing an increase in the width of the line. Theseenlarged lines (i.e., 0.5 mm>), however, are nonetheless thinner thanlines obtainable by any other known method. If desired, thicker lines(e.g., about 3 mm) can also be formed.

What is claimed is:
 1. An apparatus for making a complexly patternedflowable extrudate, comprising, in combination:means for providing afirst extrudable food material (12); means for supplying a secondflowable colored food material (18); means for forming the firstextrudable food material and the second flowable colored food materialinto a complexly patterned food mass having an initial cross sectionalarea (20); reducing passageway means for reducing the initial crosssectional area to a reduced cross sectional area of at least 25:1operatively connected to the pattern forming means having an averageconvergence angle ranging from about 5° to 45° (25) and having a largerinlet end and a smaller outlet end; and an extrudate exit port having adiameter of about the reduced cross sectional area (13) proximate theoutlet end.
 2. The apparatus of claim 1wherein the means for providingthe first extrudable food material includes at least one extrudatepassageway (14) each having an initial cross sectional area, wherein themeans for forming a complex patterned food mass includes an enlarged dieinsert (20) having an enlarged cross section relative to the crosssection of the exit port within an enlarged portion of the extrudatepassageway having a die insert diameter (21) and cross sectional areaand wherein the ratio of the die insert cross section area to thereduced cross sectional area ranges from 25 to 100:1.
 3. The apparatusof claim 2wherein the die insert (20) includes at least one food productdividing member (42) having a passageway there through (50) in fluidcommunication with the second colored food material supply means (18)and a plurality of second colored food material supply discharge holes(48).
 4. The apparatus of claim 3wherein the second colored foodmaterial supply discharge holes (48) are evenly spaced and are in thedownstream face of the die insert (20).
 5. The apparatus of claim4wherein the reducing passageway means (25) is defined by a plurality ofpieces having differing convergence angles.
 6. The apparatus of claim5wherein each passageway piece has a cross section equal to the upstreamcross section of the next downstream piece so as to form a continuouslysmooth passageway.
 7. The apparatus of claim 6wherein at least a portionof the reducing passageway means (25) has a circular cross section. 8.The apparatus of claim 6wherein at least a portion of the reducingpassageway means (25) has an irregularly shaped periphery.
 9. Theapparatus of claim 8wherein the extrudate passageway (14) includes apassageway expanding flared portion (21) immediately upstream of the dieinsert (20).
 10. The apparatus of claim 6wherein at least a portion ofthe reducing passageway means has an oval cross section.
 11. Theapparatus of claim 1wherein the means for providing a first extrudablefood material includes a means for adjusting the rate and pressure ofthe flow of the food material.
 12. The apparatus of claim 11wherein theadjusting means comprises a plug retractably extendable into the flow ofthe food material.
 13. The apparatus of claim 12wherein the means foradjusting the rate and pressure of the flow of the first extrudable foodmaterial (12) includes a circular passageway; means for adjustablyretractably extending the plug into the circular passageway includingstop means exterior to the circular passageway for terminating theextension of the plug into the circular passageway; wherein the lengthof the plug extending into the circular passageway when stopped by thestop means is less than 90% of the width of the circular passageway;means for sealing the plug against food leakage; and wherein the plugcross section is circular.
 14. An apparatus for making a complexlypatterned flowable extrudate, comprising, in combination:means forflowing a first extrudable food material (12) through a materialpassageway; a rounded smooth retractably adjustable plug projecting intothe material passageway; means for adjustably retractably extending theplug into the material passageway including stop means exterior to thematerial passageway for terminating the extension of the plug into thematerial passageway; wherein the length of the plug extending into thematerial passageway when stopped is less than 90% of the width of thematerial passageway; means for sealing the plug against food leakage;means for supplying a second flowable colored food material (18); meansfor forming the first extrudable food material and the second flowablecolored food material into a complexly patterned food mass having aninitial cross section area (20); reducing passageway means for reducingthe initial cross sectional area to be reduced cross sectional area ofat least 25:1 operatively connected to the pattern forming means havingan average convergence angle ranging from about 5° to 45° (25) andhaving a larger inlet end and a smaller outlet end; and an extrudateexit port having a diameter of about the reduced cross sectional area(13) proximate the outlet end.
 15. The apparatus of claim 1 wherein themeans for providing the first extrudable food material comprises meansfor flowing the first extrudable food material through an extrudatepassageway; and wherein the means for forming the complexly patternedfood mass comprises, in combination: means for imparting at least oneinterstitial gap in the flow of the first extrudable food material inthe extrudate passageway; and means for injecting the second flowablecolored food material into the interstitial gap in the flow of the firstextrudable food material.
 16. The apparatus of claim 15 wherein theextrudate passageway includes a divergent portion of an enlarged crosssection immediately upstream of the imparting means to widen theextrudate passageway.
 17. The apparatus of claim 15 wherein theimparting means comprises means for imparting at least one interstitialgap in a spiral pattern by die dividing members located in the flow ofthe first extrudable food material.
 18. The apparatus of claim 15wherein the extrudate passageway has a diameter of about 30 mm and thediameter of the extruder exit port is about 3 mm.
 19. The apparatus ofclaim 1 wherein the ratio of the die insert cross sectional area to thereduced cross sectional area is at least 50:1.
 20. The apparatus ofclaim 19 wherein the ratio of the die insert cross sectional area to thereduced cross sectional area is about 100:1.
 21. The apparatus of claim1 wherein the average convergence angle ranges from 5° to 20°.
 22. Theapparatus of claim 21 wherein the average convergence angle ranges from10° to 15°.
 23. The apparatus of claim 1 wherein the means for providinga first extrudable food material comprises means for providing a firstextrudable food material in the form of a dough for puffed products. 24.The apparatus of claim 13 wherein the adjustable plug includes a bolthaving threads at its outer end and a smooth portion at its inner end,with the smooth portion of the bolt extending into the circularpassageway.
 25. The apparatus of claim 13 wherein the adjustablyretractably extending means comprises threading on the adjustable plug,with the length of the threading being such that when fully threaded theplug does not choke off the circular passageway so as to minimize doughbuild-up upstream of the plug.